Free Email Deliverability API - Check SPF, DKIM, and DMARC Instantly

October 31, 2025 • InboxGreenEmail Team

Email authentication issues can hurt your inbox placement without any warning.

Run a free scan to check SPF, DKIM, DMARC, and blacklist status for your domain.

No signup required. Works on any domain.

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Meet the InboxGreen Free Email Deliverability API. One GET call returns MX, SPF, and DMARC for any domain - CORS enabled, rate limited, and production safe. Perfect for health checks, dashboards, and CI scripts.

Endpoint

GET https://inboxgreen.email/api/check?domain=example.com

Sample response

{
  "status": "ok",
  "domain": "example.com",
  "timestamp": "2025-10-31T10:10:00Z",
  "checks": {
    "mx":    { "ok": true,  "records": [ { "host": "aspmx.l.google.com", "priority": 1 } ] },
    "spf":   { "ok": true,  "record": "v=spf1 include:_spf.google.com ~all" },
    "dmarc": { "ok": false, "record": null }
  }
}

Quick start

cURL

curl "https://inboxgreen.email/api/check?domain=gmail.com"

JavaScript (browser)

<script>
fetch('https://inboxgreen.email/api/check?domain=gmail.com')
  .then(r => r.json())
  .then(d => console.log(d));
</script>

PHP

<?php
$json = file_get_contents("https://inboxgreen.email/api/check?domain=gmail.com");
$data = json_decode($json, true);
if (($data['checks']['dmarc']['ok'] ?? false) === false) {
  echo "DMARC missing";
} else {
  echo $data['checks']['dmarc']['record'];
}

Why this matters

MX: confirms receiving servers are set
SPF: lists allowed senders
DMARC: protects your brand and inbox placement

Limits & keys

Free access with modest per IP rate limiting. For bulk/commercial use or deeper checks (DKIM selectors, headers, scoring), contact us. We’ll offer a paid /api/fullcheck soon with advanced diagnostics and quotas.

Run the Free Checker Full API Docs

How to Check Email Deliverability

Manual checklist: DNS checks, inbox path testing, header reading, and ongoing monitoring.

SPF Lookup Tool

Browser-based SPF check with lookup count, syntax validation, and parsed mechanism list.

Free Deliverability Scan

Check SPF, DKIM, DMARC and List-Unsubscribe for your domain in seconds.